Ink monitoring apparatus

ABSTRACT

Apparatus for monitoring the supply of ink contained within the supply reservoir of a printing press. The ink within the reservoir is monitored by first forming it into a vortex and then monitoring a radial dimension of the vortex. According to the preferred embodiment, the monitoring structure includes a rod positioned within the reservoir which will assume a position substantially along the axis of the vortex due to the forces generated by the vortex. A follower assembly is carried by the rod and moves with it as the radius of the vortex changes due to the addition or withdrawal of ink from the reservoir. When the size of the vortex is reduced to a predetermined minimum, the follower assembly will actuate suitable apparatus to automatically add additional ink to the reservoir.

Elite States atent n 1 McCutcheon INK MONITORING APPARATUS [75] Inventor: James B. McCutcheon, Canan- [52] US. Cl ..-.101/363, 137/386, 340/244 R [51] Int. Cl. ..B41f 31/06 [58] Field of Search 101/350, 351, 363,

101/364, 366, 207, 208, 210; 141/198; l37/10l.25, 101.27, 386, 409, 413; 340/244 R, 244 B; 200/81, 81.9, 84; 222/64-69; 73/290, 305-308, 317

2,813,538 11/1957 Genova ..l01/'364 X 3,025,793 3/1962 Vischulis 101/350 3,373,052 3/1968 Rode ..340/244 R Primary Examiner-l Reed Fisher Att0rneyl 1omer 0. Blair et a1.

57 ABSTRACT Apparatus for monitoring the supply of ink contained within the supply reservoir of a printing press. The ink within the reservoir is monitored by first forming it into a vortex and then monitoring a radial dimension of the vortex. According to the preferred embodiment, the monitoring structure includes a rod positioned within the reservoir which will assume a position substantially along the axis of the vortex due to the forces generated by the vortex. A follower as sembly is carried by the rod and moves with it as the radius of the vortex changes due to the addition or withdrawal of ink from the reservoir. When the size of the vortex is reduced to a predetermined minimum, the follower assembly will actuate suitable apparatus to automatically add additional ink to the reservoir,

9 Claims, 2 Drawing Figures [56] References Cited UNITED STATES PATENTS 194,218 8/1877 Campbell 101/364 2,399,688 5/1946 Metzner et a1. 1 1 101/364 2,534,670 12/1950 Harrold l 101/364 2,570,375 10/1951 Pritchard ..137/10l.27

L/M/T SW/TCH 74 l N K 'REPLENI SH MENT CONTROL D EV ICE Patented May 1, 1973 INK REPLENISHMENT CONTROL DEVICE Jam as I Ma Cufcfieon //V VE/V TOR.

ATTO/P/VEX INK MONITORING AIPARATUS BACKGROUND OF TI-IE INVENTION 1. Field of the Invention The present invention relates to fluid monitoring apparatus. More specifically the invention relates to a system for continuously monitoring the supply of ink maintained within the ink supply reservoir of a printing press.

2. Description of the Prior Art Printing presses conventionally utilize an ink reservoir to maintain a supply of ink for use by the press and from which ink is withdrawn as needed for printing. Obviously, it is necessary that this reservoir always have a sufficient amount of ink available to satisfy any printing requirements. If the supply of ink were permitted to drop too low, many copies could be ruined causing an unnecessary loss in time and money. In addition, however, to ensuring that a sufficient amount of ink is always present in the reservoir, it is also desirable that the amount not become excessive and that only relatively small amounts of ink be maintained within the reservoir at any given time. This is to insure that the ink is kept fresh and as free from paper dust and other contaminents as possible. This requirement, however, makes it necessary to refill the reservoir fairly frequently.

Accordingly, to maintain the amount of ink in the reservoir between desired upper and lower limits becomes a real problem, particularly in view of the fact that the rate of ink usage can vary significantly from one operation to another depending on the amount of copies to be made and the type of document to be printed. Prior art systems have generally found it necessary to provide a skilled operator to watch over the press and add amounts of ink to the reservoir from time to time as needed, the amount of ink to be added and the timing of these additions being dictated by ink usage and operator experience. Such a technique is ob-. viously unsuitable for use in modern automated printing presses such as office machines and the like. In such situations it is simply not practical to have someone watch over the press. Also, it is desirable in such automated systems that the system be enclosed as much as possible so as to exclude dust and other harmful debris.

In view of these problems, it is desirable to provide a device which will reduce the need for external control by automatically monitoring the amount of ink that is present within the ink reservoir and which can either indicate when additional ink is needed or automatically add further ink to the reservoir. Unfortunately, many conventional fluid measuring techniques are not readily adaptable to the measurement of printing ink. For example, sensors or other measuring devices which make contact with the ink soon become coated with a layer of ink which then oxidizes rendering the device useless or at least requiring frequent cleaning. Also, methods employing reflection or light interruption are plagued by the random motion of the ink affecting the accuracy of the measurements.

SUMMARY OF THE INVENTION In accordancewith this invention the above and other problems are overcome by providing a novel technique for automatically monitoring the amount of ink present within the supply reservoir of the printing press. According to the invention, substantially all of the ink within the reservoir is driven into rotation to form the shape of a spinning column or vortex of ink. The size of this vortex will be directly related to the amount of ink within the reservoir and, therefore, by monitoring a dimension of this vortex, an accurate indication of the amount of ink within the reservoir may be obtained. As ink is gradually removed from the reservoir by the press, the size of the vortex will decrease and, accordingly, appropriate structure will be actuated when the monitored dimension of the vortex reaches a predetermined minimum. This structure may be in the form of a signaling device to notify the operator that further ink must be added or, alternatively, it may be a system for automatically refilling the reservoir with a new supply of ink.

The ink is caused to form into a vortex by continuous rotation of the inking roller which forms one wall of the reservoir and which carries metered amounts of ink to other components of the printing press.

In general, the present invention provides a reliable and inexpensive technique for automatically maintaining an adequate supply of ink in the ink reservoir while at the same time ensuring that the irik is kept fresh and clean by making it practical to add only small amounts to the reservoir at a time. I

BRIEF DESCRIPTION OF THE DRAWINGS FIG. ll illustrates in somewhat schematic form a plan view of the inking roller and reservoir assembly.

FIG. 2 is a cross-sectional view of the assembly of FIG. 1 showing additionally the novel ink monitoring system according to a presently preferred embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates an inking roller and reservoir assembly as conventionally employed in printing presses. Reference numeral 1 refers to the inking roller which forms the base of the reservoir designated generally by the numeral 10. The surface of this roller may be of conventional ink receptive material such as brass, copper, hard rubber, etc. and comes into direct contact with the ink in the reservoir. Suitable motor means (not shown) are provided to rotate the roller at a controllable speed in a clockwise direction as shown in the drawing. Mounted adjacent the surface of the roller 1 is a suitable metering blade 2. This blade, in conjunction with the roller surface permits metered amounts of ink to be transferred from the reservoir to other components of the press. As shown, this blade also forms one wall of the ink reservoir. A pair of side walls 3 and 4 are also provided to maintain the ink within the reservoir and to define the length of the ink vortex to be described hereinafter. If desired, a back wall 6 may also be provided to complete the reservoir. This back wall may be of soft rubber or other suitable material that will hold the ink within the reservoir without affecting the rotation of the roller 1.

FIG. 2 illustrates in a cross-sectional view, the ink reservoir assembly of FIG. 1 with the ink monitoring apparatus according to a preferred embodiment of the present invention included. As shown in FIG. 2, when a supply of ink is placed into the reservoir and the roller cause the rotated in a continuous fashion in aclockwise direction, the rotational movement of the roller surface will cause the ink to start turning in an opposite counterclockwise direction. Due to its relatively high viscosity, substantially all of the ink in the reservoir will rapidly form into a generally cylindrical shaped vortex 7. The length of this vortex will be determined by the space between side walls 3 and 4 while its diameter will depend on the amount of ink present within the reservoir. Therefore, to determine how much ink is contained within the reservoir, it becomes necessary to merely monitor a radial dimension of the vortex. FIG. 2 illustrates a presently preferred structure for accom' plishing this.

As shown in FIG. 2, an elongated member 8 such as a rod or tube is placed in the reservoir in a free-floating condition. Due to the forces of the vortex and the viscosity of the ink, this rod will assume a position approximately'along the axis of the cylindrical vortex and it will remain along the axis as the diameter of the vortex changes. Thus, by monitoring the position of this rod, the position of the axis of the vortex, and hence its radius may also be monitored. This monitoring is accomplished by means of a follower assembly 9. This as sembly includes a lever 11 having a wire loop 12 attached to one end thereof. This wire is formed as shown to provide firm, steady contact with the rod and due to its thinness will not interfere with the fluid motion in the vortex. The lever is pivoted at 13 such that it will be slightly biased against the rod to ensure that it will follow the rod at all times. A switch 14 is positioned by suitable structure not shown to be actuated by lever 11 as described hereinafter.

The operation of the system may now be described as follows: In normal operation, the system will be as indicated in FIG. 2 with the rod holding the follower assembly in the substantially horizontal position shown. As ink is gradually withdrawn from the reservoir by the inking roller, the diameter of the vortex will slowly decrease and its axis will move downwardly carrying the rod 8 along with it. Similarly, the follower assembly will follow the rod and rotate in a clockwise direction around pivot 13. At some predetermined point which can be controlled by adjusting the position of switch 14 for example, the rod and hence the follower will reach the position in which switch 14 will be actuated. This switch may be coupled to a suitable apparatus 16 for automatically adding an appropriate amount of ink from a storage bottle. Alternatively, the switch can be coupled to a signaling device to inform an operator that a new supply of ink is required. When additional ink is added, it will unite with the vortex and the vortex will increase in size raising the position of the rod. This will lever to rotate in a counterclockwise direction and again actuate the switch to stop the ink replenishing control. Hence, the ink in the reservoir may be automatically maintained between predetermined upper and lower limits.

As a specific example of a suitable system operated by the invention, an inking roller having a length of ap' proximately 9 inches and a diameter of approximately I inches was employed. The rod 8 was of brass and had a length of slightly less than 9 inches and a diameter of approximately seven-sixteenths inches. Using this structure, printing ink was formed into a suitable vortex when the inking roller was rotated at a speed sufficient to give the roller surface a tangential velocity of approximately 33 inches per second. The viscosity of the ink is not critical and in general is not well defined as it changes according to its temperature and history of motion. For example, it might vary between 60,000 and 30,000 centistokes viscosity during operation. In any event, substantially all printing inks will form into a suitable vortex over a wide range of roller speeds and viscosities.

Several distinct advantages are obtained by employing the ink monitoring system described above. Initially, because the rod is'positioned in the approximate center of the vortex, it is protected from a layer of oxidized ink forming on it. The follower assembly and in particular, the wire loop 12 in contact with the rod will also be kept relatively free from ink accumulation due to the motion of the vortex and, because of its thinness, will not interfere with the motion of the fluid in the vortex. Also, measurements will not be affected by random ink motion. Additionally, the cleanliness of the system is not particularly critical as is the case in many other known fluid measuring techniques. Furthermore, it becomes a simple matter to maintain only small amounts of ink in the reservoir to ensure freshness.

It should be understood that the above-described system is meant to be a preferred embodiment only and that the present invention might readily lend itself to various other forms. For example, in some applications it might be possible to omit the axially positioned rod and monitor the'diameter or radius of the vortex in a different manner. Furthermore it is not intented that this invention be limited to an ink supply system for printing presses but it could readily lend itself to many applications wherein fluid monitoring is required.

While there has been described and illustrated a preferred embodiment of the present invention, it is apparent that numerous alternations, omissions, and additions may be made without departing from the spirit thereof. Accordingly, the invention should be limited 0. means for forming said fluid into a spinning vortex,

the center of said vortex forming a vortex axis the position of which is indicative of the amount of fluid held within said container;

d. an elongated member positioned in said fluid in a free-floating condition and being maintained substantially along the axis of said vortex by the forces generated by said vortex; and

e. means responsive to the position of said member for monitoring the amount of fluid held within said container.

2. Apparatus as recited in claim 1 wherein said vortex forming means comprises roller means forming at least one wall of said container and wherein said apparatus further includes means for rotating said roller means, the rotation of said roller means causing said fluid to form into a vortex.

3. Apparatus as recited in claim 1 and further including means for removing fluid from said container, said removal resulting in a reduction of the radius of said vortex, and wherein said position responsive means includes means responsive to the change in position of said member as'the radius of said vortex decreases.

4. Apparatus as recited in claim 3 wherein: said position responsive means includes pivoted follower means in contact with said member and carried by said member as said member changes position, said follower means being rotatable about said pivot as said member changes position; and

switch means actuated by said follower means when the radius of said vortex has been reduced to a predetermined minimum.

5. Apparatus as recited in c1aim4 wherein at least the portion of said follower means which extends into said vortex, and is in contact with said elongated member has a thickness which is only a small fraction of the length of said vortex for preventing interference with the fluid motion within said vortex.

6. Apparatus as recited in claim 3 wherein said position responsive means further includes means for generating a signal when the radius of said vortex decreases to a predetermined minimum.

7. Apparatus a recited in claim 6 and further including means responsive to said signal for adding a new supply of fluid to said container.

8. A printing press comprising a supply reservoir for holding a supply of ink, means for transferring said ink from said reservoir to printing components of said press, and means for monitoring the amount of ink maintained in said reservoir, said monitoring means comprising:

a. a roller forming the bottom wall of said reservoir;

b. means for rotating said roller, the rotation of said roller forming at least 'a portion of the ink in said reservoir into a vortex, the center of said vortex forming a vortex axis extending substantially parallel to said roller whereby the position of said vortex axis is indicative of the amount of ink held within said reservoir;

0. a rod positioned in said reservoir in a substantially free-floating condition, said rod being maintained substantially along the axis of said vortex by the forces generated by said vortex; and

. detecting means coupled to said rod for detecting changes in the position of said rod as the radius of said vortex decreases due to the withdrawal of ink from said reservoir.

9. Apparatus as recited in claim 8 and further including means responsive to said detecting means for adding ink to said reservoir when the radius of said vortex decreases to a predetermined minimum. 

1. Fluid monitoring apparatus comprising: a. a container; b. a supply of fluid held within said container; c. means for forming said fluid into a spinning vortex, the center of said vortex forming a vortex axis the position of which is indicative of the amount of fluid held within said container; d. an elongated member positioned in said fluid in a freefloating condition and being maintained substantially along the axis of said vortex by the forces generated by said vortex; and e. means responsive to the position of said member for monitoring the amount of fluid held within said container.
 2. Apparatus as recited in claim 1 wherein said vortex forming means comprises roller means forming at least one wall of said container and wherein said apparatus further includes means for rotating said roller means, the rotation of said roller means causing said fluid to form into a vortex.
 3. Apparatus as recited in claim 1 and further including means for removing fluid from said container, said removal resulting in a reduction of the radius of said vortex, and wherein said position responsive means includes means responsive to the change in position of said member as the radius of said vortex decreases.
 4. Apparatus as recited in claim 3 wherein: said position responsive means includes pivoted follower means in contact with said member and carried by said member as said member changes position, said follower means being rotatable about said pivot as said member changes position; and switch means actuated by said follower means when the radius of said vortex has been reduced to a predetermined minimum.
 5. Apparatus as recited in claim 4 wherein at least the portion of said follower means which extends into said vortex, and is in contact with said elongated member has a thickness which is only a small fraction of the length of said vortex for preventing interference with the fluid motion within said vortex.
 6. Apparatus as recited in claim 3 wherein said position responsive means further includes means for generating a signal when the radius of said vortex decreases to a predetermined minimum.
 7. Apparatus a recited in claim 6 and further including means responsive to said signal for adding a new supplY of fluid to said container.
 8. A printing press comprising a supply reservoir for holding a supply of ink, means for transferring said ink from said reservoir to printing components of said press, and means for monitoring the amount of ink maintained in said reservoir, said monitoring means comprising: a. a roller forming the bottom wall of said reservoir; b. means for rotating said roller, the rotation of said roller forming at least a portion of the ink in said reservoir into a vortex, the center of said vortex forming a vortex axis extending substantially parallel to said roller whereby the position of said vortex axis is indicative of the amount of ink held within said reservoir; c. a rod positioned in said reservoir in a substantially free-floating condition, said rod being maintained substantially along the axis of said vortex by the forces generated by said vortex; and d. detecting means coupled to said rod for detecting changes in the position of said rod as the radius of said vortex decreases due to the withdrawal of ink from said reservoir.
 9. Apparatus as recited in claim 8 and further including means responsive to said detecting means for adding ink to said reservoir when the radius of said vortex decreases to a predetermined minimum. 